Ultrafast Route Research Articles

A new fabricated hetero-atom doped carbon quantum dots as a fluorescent probe for metronidazole determination using garlic and red lentils with microwave assistance.

Biocompatible and highly fluorescent phosphorus, nitrogen and sulfur carbon quantum dots (P,N,S-CQDs) were synthesized using a quick and ecologically friendly process inspired from plant sources. Garlic and red lentils were utilized as natural and inexpensive sources for efficient synthesis of the carbon-based quantum dots using green microwave-irradiation, which provides an ultrafast route for carbonization of the organic biomass and subsequent fabrication of P,N,S-CQDs within only 3 min. The formed P,N,S-CQDs showed excellent blue fluorescence at λem= 412 nm when excited at 325 nm with a quantum yield up to 26.4%. These fluorescent dots were used as a nano-sensor for the determination of the commonly used antibacterial and antiprotozoal drug, metronidazole (MTR). As MTR lacked native fluorescence and prior published techniques had several limitations, the proposed methodology became increasingly relevant. This approach affords sensitive detection with a wide linear range of 0.5-100.0μM and LOD and LOQ values of 0.14 μM and 0.42 μM, respectively. As well as, it is cost-effective and ecologically benign. The MTT test was used to evaluate the in-vitro cytotoxicity of the fabricated P,N,S-CQDs. The findings supported a minimally cytotoxic impact and good biocompatibility, which provide a future perspective for the applicability of these CQDs in biomedical applications.

Synthesis and Structural Analysis of High-Silica ERI Zeolite with Spatially-Biased Al Distribution as a Promising NH3-SCR Catalyst.

Erionite (ERI) zeolite has recently attracted considerable attention for its application prospect in the selective catalytic reduction of NOx with NH3 (NH3-SCR), provided that the high-silica (Si/Al > 5.5) analog with improved hydrothermal stability can be facilely synthesized. In this work, ERI zeolites with different Si/Al ratios (4.6, 6.4, and 9.1) are synthesized through an ultrafast route, and in particular, a high-silica ERI zeolite with a Si/Al ratio of 9.1 is obtained by using faujasite (FAU) as a starting material. The solid-state 29Si MAS NMR spectroscopic study in combination with a computational simulation allows for figuring out the atomic configurations of the Al species in the three ERI zeolites. It is revealed that the ERI zeolite with the highest Si/Al ratio (ERI-9.1, where the number indicates the Si/Al ratio) exhibits a biased Al occupancy at T1 site, which is possibly due to the presence of a higher fraction of the residual potassium cations in the can cages. In contrast, the Al siting in ERI-4.6 and ERI-6.4 proves to be relatively random.

Ultra-fast route to fabricate large-area anode-supported solid oxide fuel cell via microwave-assisted sintering

Herein, a practical, facile, and ultra-fast technique to fabricate a large-area multi-layered solid oxide fuel cell (SOFC) is reported. In this technique, a total 25 tape-casted green films of anode-support layer, anode functional layer (AFL), electrolyte layer, and buffer layer were sequentially co-laminated and co-sintered at 1250 °C using microwave energy (2.45 GHz) in a record short time of 90 min. This process is 16 times faster than the conventional sintering process. The microwave-assisted sintering method enhanced the densification of the electrolyte and buffer layer by directly transferring the heat into the cell material. Despite the incredibly rapid processing time, the microwave-assisted sintered cell showed improved interfacial connectivity of the electrolyte and buffer layer in comparison to the conventionally sintered cell. The large-area (6 cm × 6 cm) SOFC fabricated through this route showed a maximum power density of 1.05 Wcm-2 at 750 °C. Moreover, the cell showed exceptional long-term stability tested under a constant current of 10 A for 500 h at 750 °C. The approach seems appealing in terms of its rapidity, simplicity, economic viability, and applicability in multi-layer energy devices.

Highly Effective Self-Propagating Synthesis of Lamellar ZnO-Decorated MnO2 Nanocrystals with Improved Supercapacitive Performance.

A series of MOx (M = Co, Ni, Zn, Ce)-modified lamellar MnO2 electrode materials were controllably synthesized with a superfast self-propagating technology and their electrochemical practicability was evaluated using a three-electrode system. The results demonstrated that the specific capacitance varied with the heteroatom type as well as the doping level. The low ZnO doping level was more beneficial for improving electrical conductivity and structural stability, and Mn10Zn hybrid nanocrystals exhibited a high specific capacitance of 175.3 F·g−1 and capacitance retention of 96.9% after 2000 cycles at constant current of 0.2 A·g−1. Moreover, XRD, SEM, and XPS characterizations confirmed that a small part of the heteroatoms entered the framework to cause lattice distortion of MnO2, while the rest dispersed uniformly on the surface of the carrier to form an interfacial collaborative effect. All of them induced enhanced electrical conductivity and electrochemical properties. Thus, the current work provides an ultrafast route for development of high-performance pseudocapacitive energy storage nanomaterials.

Ultrafast Microwave Activating Polarized Electron for Scalable Porous Al toward High-Energy-Density Batteries.

Chemical etching of metals generally brings about undesirable surface damage accompanied by deteriorated performance. However, new possibilities in view of structured interfaces and functional surfaces can be explored by wisely incorporating corrosion chemistry. Here, an ultrafast route to scalable Al foils with desired porous structures originating from Fe(III)-induced oxidation etching was presented. Coupling with efficient electron polarization involving microwave interaction, straightforward surface engineering is well established on various commercial Al foils within minutes, which can be successfully extended to bulk Al alloys. As a proof-of-concept demonstration, the well-defined porous Al foils featuring regulated surface energy, demonstrate great potential as current collectors in promoting cycling stability, for example, 85.2% reversible capacity sustained after 550 cycles (comparable to commercial Al/C foils), and energy density, that is, approximately 3 times of that by using pristine Al foils for LiFePO4-Li half cells.

Green synthesis of hierarchically porous Cu- and Zn-MOFs by the combined action of hydroxy double salt and surfactant: An ultrafast method

Hierarchically porous MOFs have raised considerable interest recently, due to their variety potential applications in adsorption, separation of molecules, drug delivery, catalysis etc. Presence of mesopores (2–50 nm) along with micropores (<2 nm) in the MOF networks enable them to be used as hosts to accommodate molecules, which enable their reaction or transformation. Even though a number of approaches were explored recently to generate cavities in MOFs resulting in hierarchically structured materials, most of the methods require harsh experimental conditions and tedious down-stream treatments which are energy consuming, having potential risk of pollution and low production rate. In this work we report a simple, green and ultrafast route for the synthesis of two HP-MOFs (Cu-BDC MOF and Zn-BDC MOF) using the cooperative template strategy by the simultaneous introduction of ZnO as the accelerator and cetyltrimethylammonium bromide (CTAB) as the surfactant. ZnO was employed to accelerate the construction of the framework by the formation of hydroxy double salt (HDS) layers whereas CTAB was introduced as surfactant for the formation of template micelles which guide the formation of micro- and mesopores through a synergistic effect with the HDS. The advantage of this method is that the synthetic procedure was accomplished in a few minutes (6 min) at room temperature and pressure and this ultrafast synthetic approach provide a new route of synthesizing hierarchically porous MOFs with high space-time yields (STYs).

Room-temperature ultrafast synthesis, morphology and upconversion luminescence of K0.3Bi0.7F2.4:Yb3+/Er3+ nanoparticles for temperature-sensing application

This manuscript describes an ultrafast route at room temperature for the synthesis of the K0.3Bi0.7F2.4 nanoparticles with photoluminescence and luminescent temperature sensing.

Ultra-fast route to synthesizing biogenic carbonate hydroxyapatite: Consequence of a high-pressure solid-solid preparation technique

We employed a high-pressure solid–solid preparation technique in CO2 to synthesize carbonate hydroxyapatite (CHAp) powders from solid calcium and phosphate precursors. The synthesis parameters were investigated and optimized to determine the best precursor and optimal synthesis conditions. The results showed that the technique is green and that the biogenic calcium from eggshells in supercritical CO2 yielded B-type CHAp with desirable and recommended carbonate contents (4.1–5.1 wt %). The biogenic calcium source also yielded product with excellent surface area (212.4m2/g) and pore volume (0.65 cm3/g) compared to the synthetic calcium source, which exhibited high ibuprofen loading (270.0 mg/g) and enhanced dissolution (100% in 6 h) in simulated gastric fluid. These results indicate that the CHAp has potential for medical and other related applications. Mechanism study revealed that the procedure is a self-catalytic reaction triggered by water in the reactants with short time, which can overcome the disadvantages of existing techniques commendably.

Ultrafast synthesis of zeolites: breakthrough, progress and perspective

An ultrafast route was established to synthesize industrially important zeolites in several minutes, which represents a breakthrough in the field of zeolite synthesis.

A Green, General, and Ultrafast Route for the Synthesis of Diverse Metal Oxide Nanoparticles with Controllable Sizes and Enhanced Catalytic Activity

A green, efficient, simple, and general route has been developed to synthesize a wide variety of metal oxide nanoparticles (NPs) in large quantities at room temperature. Various metal and alloy oxi...

Ultrafast synthesis of bifunctional Er3+/Yb3+-codoped NaBiF4 upconverting nanoparticles for nanothermometer and optical heater

We reported a simple and ultrafast route to synthesize the bifunctional Er3+/Yb3+-codoped NaBiF4 upconverting nanoparticles. It was found that the phase composition and microstructure of the prepared samples were strongly dependent on the NH4F content. When the NH4F content was 14 mmol, after 1 min reaction at room temperature, the resultant compounds exhibited pure single phase and were composed of uniform spherical nanoparticles. Under 980 nm light irradiation, the synthesized nanoparticles emitted visible emissions originating from the intra-4f transitions of Er3+ ions and the involved upconversion luminescence mechanism was associated with the typical two-photon process. With the aid of the fluorescence intensity ratio technique, the optical thermometric behaviors of the studied nanoparticle based on the (2H11/2,4S3/2) thermally-coupled levels in the temperature range of 303–483 K were systematically analyzed and the maximum sensor sensitivity was determined to be about 0.0057 K−1 at 483 K. Furthermore, the internal heating properties of the resultant nanoparticles induced by the laser power source were also studied. With elevating the pump power from 159 to 658 mW, the temperature of the upconverting nanoparticles was improved from 304 to 464 K. These results suggest that the Er3+/Yb3+-codoped NaBiF4 upconverting nanoparticles are promising bifunctional luminescent materials for nanothermometer and optical heater applications.

Ultrafast Synthesis and Coating of High-Quality β-NaYF4:Yb3+,Ln3+ Short Nanorods.

An ultrafast route to prepare up-converting single β-phase NaYF4:Yb3+,Ln3+ (Ln: Er, Tm, or Tb) short nanorods (UCNRs) of high quality was developed. This new procedure affords reactive-surface nanorods that are easily coated by direct injection of suitable capping ligands. Thus highly crystalline nanorods with excellent UC fluorescence and good solvent-selective dispersion are obtained, which represents a significant advance in the field and enlarges their use for biomedical and other technological applications. Unlike other methodologies, the short reaction time provides a kinetic control over crystallization processes, and the β-phase and rod morphology is preserved regardless of the optically active Ln3+ ion. The UC emission was finely tuned by using the most popular Yb3+/Tm3+ and Yb3+/Er3+ pairs. More importantly, UCNRs doped with the unusual Yb3+/Tb3+ pair, with no ladder-like energy levels, provided a nice emission upon near-infrared excitation, which constitutes the first example of phonon-assisted cooperative sensitization to date in pure β-NaYF4 nanocrystals.

Ultrafast and large scale preparation of superior catalyst for oxygen evolution reaction

The development of efficient and earth abundant catalyst for the oxygen evolution reaction (OER) is a key challenge for the renewable energy research community. Here, we report a facile and ultrafast route to immobilize nickel-iron layered double hydroxide (NiFe-LDH) nanoparticles on nickel foam (NF) via soaking the direct electroless deposited prussian blue analogue (PBA) on NF in 1 M KOH. This NiFe-LDH/NF electrode can be prepared in a few seconds without further treatments. It has three-dimensional interpenetrating network originated from its PBA precursor which facilitate the diffusion and ad/desorption of the reactants and producing for OER. And further characterization of the Faradaic efficiency and forced convection tests show direct evidence to demonstrate the formation of free intermediate(s) in the OER process. This electrode (typically NiFe-LDH-20s/NF) exhibits outstanding electrocatalytic activity with low overpotential of ∼0.240 V at 10 mA cm−2, low Tafel slope of 38 mV dec−1, and great stability. This feasible strategy affords a new strategy for the large scale manufacture of low-cost, effective and robust OER electrodes.

An Environmentally Benign Antimicrobial Coating Based on a Protein Supramolecular Assembly.

The use of antimicrobial materials, for example, silver nanoparticles, has been a cause for concern because they often exert an adverse effect on environmental and safety during their preparation and use. In this study, we report a class of green antimicrobial coating based on a supramolecular assembly of a protein extracted from daily food, without the addition of any other hazardous agents. It is found that a self-assembled nanofilm by mere hen egg white lysozyme has durable in vitro and in vivo broad-spectrum antimicrobial efficacy against Gram-positive/negative and fungi. Such enhanced antimicrobial capability over native lysozyme is attributed to a synergistic combination of positive charge and hydrophobic amino acid residues enriched on polymeric aggregates in the lysozyme nanofilm. Accompanied with high antimicrobial activity, this protein-based PTL material simultaneously exhibits the integration of multiple functions including antifouling, antibiofilm, blood compatibility, and low cytotoxicity due to the existence of surface hydration effect. Moreover, the bioinspired adhesion mediated by the amyloid structure contained in the nanofilm induces robust transfer and self-adhesion of the material onto virtually arbitrary substrates by a simple one-step aqueous coating or solvent-free printing in 1 min, thereby allowing an ultrafast route into practical implications for surface-functionalized commodity and biomedical devices. Our results demonstrate that the application of pure proteinaceous substance may afford a cost-effective green biomaterial that has high antimicrobial activity and low environmental impact.

Widening Synthesis Bottlenecks: Realization of Ultrafast and Continuous‐Flow Synthesis of High‐Silica Zeolite SSZ‐13 for NOx Removal

AbstractCharacteristics of zeolite formation, such as being kinetically slow and thermodynamically metastable, are the main bottlenecks that obstruct a fast zeolite synthesis. We present an ultrafast route, the first of its kind, to synthesize high‐silica zeolite SSZ‐13 in 10 min, instead of the several days usually required. Fast heating in a tubular reactor helps avoid thermal lag, and the synergistic effect of addition of a SSZ‐13 seed, choice of the proper aluminum source, and employment of high temperature prompted the crystallization. Thanks to the ultra‐short period of synthesis, we established a continuous‐flow preparation of SSZ‐13. The fast‐synthesized SSZ‐13, after copper‐ion exchange, exhibits outstanding performance in the ammonia selective catalytic reduction (NH3‐SCR) of nitrogen oxides (NOx), showing it to be a superior catalyst for NOx removal. Our results indicate that the formation of high‐silica zeolites can be extremely fast if bottlenecks are effectively widened.

Widening Synthesis Bottlenecks: Realization of Ultrafast and Continuous-Flow Synthesis of High-Silica Zeolite SSZ-13 for NOx Removal.

Characteristics of zeolite formation, such as being kinetically slow and thermodynamically metastable, are the main bottlenecks that obstruct a fast zeolite synthesis. We present an ultrafast route, the first of its kind, to synthesize high-silica zeolite SSZ-13 in 10 min, instead of the several days usually required. Fast heating in a tubular reactor helps avoid thermal lag, and the synergistic effect of addition of a SSZ-13 seed, choice of the proper aluminum source, and employment of high temperature prompted the crystallization. Thanks to the ultra-short period of synthesis, we established a continuous-flow preparation of SSZ-13. The fast-synthesized SSZ-13, after copper-ion exchange, exhibits outstanding performance in the ammonia selective catalytic reduction (NH3 -SCR) of nitrogen oxides (NOx ), showing it to be a superior catalyst for NOx removal. Our results indicate that the formation of high-silica zeolites can be extremely fast if bottlenecks are effectively widened.

Excited state evolution towards ligand loss and ligand chelation at group 6 metal carbonyl centres.

The photochemistry and photophysics of three model "half-sandwich" complexes (η(6)-benzophenone)Cr(CO)3, (η(6)-styrene)Cr(CO)3, and (η(6)-allylbenzene)Cr(CO)3 were investigated using pico-second time-resolved infrared spectroscopy and time-dependent density functional theory methods. The (η(6)-benzophenone)Cr(CO)3 complex was studied using two excitation wavelengths (470 and 320 nm) while the remaining complexes were irradiated using 400 nm light. Two independent excited states were detected spectroscopically for each complex, one an unreactive excited state of metal-to-arene charge-transfer character and the other with metal-to-carbonyl charge transfer character. This second excited state leads to an arrested release of CO on the pico-second time-scale. Low-energy excitation (470 nm) of (η(6)-benzophenone)Cr(CO)3 populated only the unreactive excited state which simply relaxes to the parent complex. Higher energy irradiation (320 nm) induced CO-loss. Irradiation of (η(6)-styrene)Cr(CO)3, or (η(6)-allylbenzene)Cr(CO)3 at 400 nm provided evidence for the simultaneous population of both the reactive and unreactive excited states. The efficiency at which the unreactive excited state is populated depends on the degree of conjugation of the substituent with the arene π-system and this affects the efficiency of the CO-loss process. The quantum yield of CO-loss is 0.50 for (η(6)-allylbenzene)Cr(CO)3 and 0.43 for (η(6)-styrene)Cr(CO)3. These studies provide evidence for the existence of two photophysical routes to CO loss, a minor ultrafast route and an arrested mechanism involving the intermediate population of a reactive excited state. This reactive excited state either relaxes to reform the parent species or eject CO. Thus the quantum yield of the CO-loss is strongly dependent on the excitation wavelength. Time-dependent density functional theory calculations confirm that the state responsible for ultrafast CO-loss has significant metal-centred character while the reactive state responsible for the arrested CO-loss has significant metal-to-carbonyl charge-transfer character. The CO-loss product (η(6)-allylbenzene)Cr(CO)2 formed following irradiation of (η(6)-allylbenzene)Cr(CO)3 reacts further with the pendent alkenyl group to form the chelate product (η(6),η(2)-allylbenzene)Cr(CO)2.

Microwave-assisted hydrothermal crystallization: an ultrafast route to MSP@mTiO2 composite microspheres with a uniform mesoporous shell

An ultrafast, green and efficient microwave-assisted hydrothermal crystallization method was developed to convert the amorphous titania shell of MSP@TiO2 to uniform mesoporous anatase structure for highly selective and effective enrichment of phosphopeptides.

Ultra-fast surface hydrophobic modification of sol–gel silica antireflective coating with enhanced abrasion-resistance

A novel and ultra-fast route was proposed to modify the surface hydrophobicity of sol–gel silica antireflective (AR) coating with poly(methylhydrogen)siloxane (PMHS). The hydroxyl groups on silica particle are thought to react with the hydrogen atoms within several seconds at room temperature in the presence of platinum catalyst. The surface modification can be accomplished simply by immerging silica AR coating into the PMHS/hexane solution containing platinum catalyst and then withdrawing immediately from the solution. The hydrophobicity and abrasion-resistance of PMHS modified AR coating were significantly improved. This provides a new method for the preparation of abrasion-resistant sol–gel silica AR coating used in outdoor environment.

Nonlinear phononics as an ultrafast route to lattice control

To date, two types of coupling between electromagnetic radiation and a crystal lattice have been identified experimentally. One is direct, for infrared (IR)-active vibrations that carry an electric dipole. The second is indirect, it occurs through intermediate excitation of the electronic system via electron-phonon coupling, as in stimulated Raman scattering. Nearly 40 years ago, proposals were made of a third path, referred to as ionic Raman scattering (IRS). It was posited that excitation of an IR-active phonon could serve as the intermediate state for a Raman scattering process relying on lattice anharmonicity as opposed to electron phonon interaction. In this paper, we report an experimental demonstration of ionic Raman scattering and show that this mechanism is relevant to optical control in solids. The key insight is that a rectified phonon field can exert a directional force onto the crystal, inducing an abrupt displacement of the atoms from the equilibrium positions that could not be achieved through excitation of an IR-active vibration alone, for which the force is oscillatory. IRS opens up a new direction for the coherent control of solids in their electronic ground state, different from approaches that rely on electronic excitations.